Beyond species means – the intraspecific contribution to global wood density variation
Fabian Jörg Fischer, Jérôme Chave, Amy Zanne, Tommaso Jucker, Alex Fajardo, Adeline Fayolle, Renato Augusto Ferreira de Lima, Ghislain Vieilledent, Hans Beeckman, Wannes Hubau, Tom De Mil, Daniel Wallenus, Ana María Aldana, Esteban Alvarez‐Dávila, Luciana F. Alves, Deborah M. G. Apgaua, Fátima Arcanjo, Jean‐François Bastin, Andrii Bilous, Philippe Birnbaum, Volodymyr Blyshchyk, Joli Borah, Vanessa Boukili, J. Julio Camarero, Luisa Casas, Roberto Cazzolla Gatti, Jeffrey Q. Chambers, Ezequiel Chimbioputo Fabiano, Brendan Choat, Georgina Conti, Will Cornwell, Javid Ahmad Dar, Ashesh Kumar Das, Magnus Dobler, Dao Dougabka, David P. Edwards, Robert Evans, Daniel Falster, Philip Fearnside, Olivier Flores, Nikolaos Fyllas, Jean Gérard, Rosa C. Goodman, Daniel Guibal, L. Francisco Henao‐Diaz, Vincent Hervé, Peter Hietz, Jürgen Homeier, Thomas Ibanez, Jugo Ilic, Steven Jansen, Rinku Moni Kalita, Tanaka Kenzo, Liana Kindermann, Subashree Kothandaraman, Martyna Kotowska, Yasuhiro Kubota, Patrick Langbour, James Lawson, André Luiz Alves de Lima, Roman Mathias Link, Anja Linstädter, Rosana López, Cate Macinnis‐Ng, Luiz Fernando S. Magnago, Adam R. Martin, Ashley M. Matheny, James K. McCarthy, Regis B. Miller, Arun Jyoti Nath, Bruce Walker Nelson, Marco Njana, Euler Melo Nogueira, Alexandre Oliveira, Rafael Oliveira, Mark Olson, Yusuke Onoda, Keryn Paul, Daniel Piotto, Phil Radtke, Onja Razafindratsima, Tahiana Ramananantoandro, Jennifer Read, Sarah Richardson, Enrique G. de la Riva, Oris Rodríguez‐Reyes, Samir G. Rolim, Victor Rolo, Julieta A. Rosell, Roberto Salguero‐Gómez, Nadia S. Santini, Bernhard Schuldt, Luitgard Schwendenmann, Arne Sellin, Timothy Staples, Pablo R. Stevenson, Somaiah Sundarapandian, Masha T. van der Sande, Bernard Thibaut, David Yue Phin Tng
Abstract
Summary Wood density is central for estimating vegetation carbon storage and a plant functional trait of great ecological and evolutionary importance. However, the global extent of wood density variation is unclear, especially at the intraspecific level. We assembled the most comprehensive wood density collection to date, including 109 626 records from 16 829 plant species across woody life forms and biomes (GWDD v.2, available here: doi: 10.5281/zenodo.16919509 ). Using the GWDD v.2, we explored the sources of wood density variation within individuals, within species and across environmental gradients. Intraspecific variation accounted for c . 15% of overall wood density variation (SD = 0.068 g cm −3 ). Variance was 50% smaller in sapwood than heartwood, and 30% smaller in branchwood than trunkwood. Individuals in extreme environments (dry, hot and acidic soils) had higher wood density than conspecifics elsewhere (+0.02 g cm −3 , c . 4% of the mean). Intraspecific environmental effects strongly tracked interspecific patterns ( r = 0.83) but were 70–80% smaller and varied considerably among taxa. Individual plant wood density was difficult to predict (root mean square error > 0.08 g cm −3 ; single‐measurement R 2 = 0.59). We recommend: (1) systematic sampling of multiple individuals and tissues for local applications; and (2) expanded taxonomic coverage combined with integrative models for robust estimates across ecological scales.